Polyurea or polyurethane capsules

Abstract

Polyurea capsule compositions. A subset of these compositions contain a plurality of capsules and a capsule formation aid, in which each of the capsules contains a polyurea wall and an oil core; the polyurea wall is formed of a reaction product of a polyisocyanate and a cross-linking agent in the presence of the capsule formation aid; and the oil core contains an active material. The polyisocyante, cross-linking agent, and capsule formation aids are described herein. Also disclosed are methods of preparing polyurea capsule compositions, as well as consumer products containing one of these compositions.

What is claimed is: 
     
       1. A method of preparing a capsule composition comprising the steps of:
 (a) providing an active emulsion containing droplets of a water-immiscible phase and an aqueous phase, 
 (b) causing formation of capsules in the active emulsion, in the presence of (i) gum Arabic or (ii) polyvinylpyrrolidone and a copolymer of vinyl pyrrolidone and quaternized dimethylaminoethyl methacrylate, by adding a catalyst to obtain a capsule slurry; and 
 (c) curing the capsule slurry thereby obtaining the capsule composition, 
 wherein the capsule composition has capsules each containing a capsule wall and a capsule core, the capsule wall encapsulates the capsule core, the active emulsion contains a polyisocyanate and a pectin or guar gum. 
 
     
     
       2. The method of  claim 1 , further comprising the step of (d) adding a deposition aid to the capsule slurry. 
     
     
       3. The method of  claim 1 , wherein the active material is a fragrance, flavor, malodor counteracting agent, or combination thereof. 
     
     
       4. The method of  claim 1 , wherein the polyisocyanate is an aromatic polyisocyanate, aliphatic polyisocyanate, or combination thereof; the aromatic polyisocyanate contains a phenyl moiety, a tolyl moiety, a xylyl moiety, a naphthyl moiety, a diphenyl moiety, or a combination thereof; and the aliphatic polyisocyanate is a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, a biuret of hexamethylene diisocyanate, or a combination thereof. 
     
     
       5. The method of  claim 4 , wherein the aromatic polyisocyanate is selected from the group consisting of a polyisocyanurate of toluene diisocyanate, a trimethylol propane-adduct of toluene diisocyanate, a trimethylol propane-adduct of xylylene diisocyanate, and combinations thereof; and the aliphatic polyisocyanate is based on hexamethylene diisocyanate. 
     
     
       6. The method for  claim 1 , further comprising step (d) purifying the capsule composition by washing with water, diafiltration, or centrifugation. 
     
     
       7. The method of  claim 1 , wherein the capsule core further contains a solvent or core modifier. 
     
     
       8. The method of  claim 1 , wherein the active emulsion is prepared by emulsifying an oil phase into an aqueous phase, and the oil phase comprises the active material. 
     
     
       9. A capsule composition prepared by the method of  claim 1 . 
     
     
       10. A consumer product comprising a capsule composition of  claim 9 .